Almost working, hacked together Docker CI setup

Resources found from:
https://github.com/utensils/docker-opengl
https://gist.github.com/baryluk/1041204eff4cc4fad6f1508afe67b562

.dockerignore

@@ -0,0 +1,4 @@
+.git/
+bin/
+
+Dockerfile

Dockerfile

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+# Base Docker Image
+ARG BASE_IMAGE=alpine:3.13
+FROM ${BASE_IMAGE} as builder
+
+# Install all needed build deps for Mesa3D
+ARG LLVM_VERSION=10
+RUN set -xe; \
+    apk add --no-cache \
+        autoconf \
+        automake \
+        bison \
+        build-base \
+        cmake \
+        elfutils-dev \
+        expat-dev \
+        flex \
+        gettext \
+        git \
+        glproto \
+        libdrm-dev \
+        libtool \
+        libva-dev \
+        libx11-dev \
+        libxcb-dev \
+        libxdamage-dev \
+        libxext-dev \
+        libxfixes-dev \
+        libxrandr-dev \
+        libxshmfence-dev \
+        libxt-dev \
+        libxvmc-dev \
+        libxxf86vm-dev \
+        llvm${LLVM_VERSION} \
+        llvm${LLVM_VERSION}-dev \
+        makedepend \
+        meson \
+        py-mako \
+        py3-libxml2 \
+        py3-mako \
+        python3 \
+        python3-dev \
+        talloc-dev \
+        wayland-dev \
+        wayland-protocols \
+        xorg-server-dev \
+        xorgproto \
+        zlib-dev \
+        zstd-dev;
+
+# Clone Mesa source repo. (this step caches)
+# Due to ongoing packaging issues we build from git vs tar packages
+# Refer to https://bugs.freedesktop.org/show_bug.cgi?id=107865
+ARG MESA_VERSION=21.1.1
+RUN set -xe; \
+    mkdir -p /var/tmp/build; \
+    cd /var/tmp/build/; \
+    git clone --depth=1 --branch=mesa-${MESA_VERSION} https://gitlab.freedesktop.org/mesa/mesa.git;
+
+# Build Mesa from source.
+ARG BUILD_TYPE=release
+ARG BUILD_OPTIMIZATION=3
+RUN set -xe; \
+    cd /var/tmp/build/mesa; \
+    libtoolize; \
+    if [ "$(uname -m)" ==  "aarch64" ] || [ "$(uname -m)" == "armv7l" ]; \
+    then \
+        galium_drivers=swrast; \
+    else \
+        galium_drivers=swrast,swr; \
+    fi ;\
+    meson \
+        --buildtype=${BUILD_TYPE} \
+        --prefix=/usr/local \
+        --sysconfdir=/etc \
+        -D b_ndebug=true \
+        -D egl=true \
+        -D gallium-nine=false \
+        -D gallium-xvmc=false \
+        -D gbm=true \
+        -D gles1=false \
+        -D gles2=true \
+        -D opengl=true \
+        -D dri-drivers-path=/usr/local/lib/xorg/modules/dri \
+        -D dri-drivers= \
+        -D dri3=true  \
+        -D egl=false \
+        -D gallium-drivers="$galium_drivers" \
+        -D gbm=false \
+        -D glx=dri \
+        -D llvm=true \
+        -D lmsensors=false \
+        -D optimization=${BUILD_OPTIMIZATION} \
+        -D osmesa=true  \
+        -D platforms=x11,wayland \
+        -D shared-glapi=true \
+        -D shared-llvm=true \
+        -D vulkan-drivers= \
+        build/; \
+    ninja -C build/ -j $(getconf _NPROCESSORS_ONLN); \
+    ninja -C build/ install;
+
+# The specs are built as a static program and copied to an environment that can run OpenGL apps.
+FROM crystallang/crystal:1.0.0-alpine as app
+RUN apk add --update --no-cache glfw-dev
+COPY . ./
+# RUN crystal build --static specs.cr
+RUN crystal build specs.cr
+
+# Create fresh image from alpine
+FROM alpine:3.13
+
+# Install runtime dependencies for Mesa and link xorg dri modules
+ARG LLVM_VERSION=10
+RUN set -xe; \
+    apk --update add --no-cache \
+        pcre \
+        gc \
+        glfw \
+        binutils \
+        expat \
+        llvm${LLVM_VERSION}-libs \
+        setxkbmap \
+        xdpyinfo \
+        xrandr \
+        xvfb \
+        xvfb-run \
+        zstd-libs; \
+    ln -sf /usr/local/lib/xorg/modules/dri/* /usr/lib/xorg/modules/dri/
+
+# Setup our environment variables.
+ENV \
+    GALLIUM_DRIVER="llvmpipe" \
+    LD_LIBRARY_PATH="/usr/local/lib:$LD_LIBRARY_PATH" \
+    LIBGL_ALWAYS_SOFTWARE="1" \
+    LP_DEBUG="" \
+    LP_NO_RAST="false" \
+    LP_NUM_THREADS="" \
+    LP_PERF="" \
+    XVFB_WHD="1920x1080x24"
+
+# Copy the Mesa build & entrypoint script from previous stage
+COPY --from=builder /usr/local /usr/local
+COPY entrypoint.sh /usr/local/bin/
+COPY --from=app specs /usr/local/bin/
+
+# Set the entrypoint script
+ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
+CMD ["/usr/local/bin/specs"]

entrypoint.sh

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+#!/bin/sh
+
+xvfb-run -a -s "-screen 0 '${XVFB_WHD}' -nolisten tcp +extension GLX +render -noreset" "$@"

spec/spec_helper.cr

@@ -5,7 +5,12 @@ require "../src/gloop"
 
 # Initializes OpenGL enough for testing.
 def init_opengl
-  LibGLFW.init
+  if LibGLFW.init.zero?
+    error = LibGLFW.get_error(out description)
+    description = String.new(description)
+    raise "Failed to initialize GLFW - #{error} - #{description}"
+  end
+
   LibGLFW.window_hint(LibGLFW::WindowHint::Visible, LibGLFW::Bool::False)
   LibGLFW.window_hint(LibGLFW::WindowHint::ContextVersionMajor, 4)
   LibGLFW.window_hint(LibGLFW::WindowHint::ContextVersionMinor, 6)

specs.cr

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+require "./spec/**"